+ when creating picture check whether pbuffer is supported

src/Gui/Thumbnail.cpp

@@ -30,6 +30,7 @@
 # include <QDateTime>
 # include <QImage>
 # include <QGLFramebufferObject>
+# include <QGLPixelBuffer>
 #endif
 
 #include "Thumbnail.h"
@@ -86,8 +87,9 @@ void Thumbnail::SaveDocFile (Base::Writer &writer) const
     if (!this->viewer)
         return;
     QImage img;
+    bool pbuffer = QGLPixelBuffer::hasOpenGLPbuffers();
     if (App::GetApplication().GetParameterGroupByPath
-        ("User parameter:BaseApp/Preferences/Document")->GetBool("DisablePBuffers",false)) {
+        ("User parameter:BaseApp/Preferences/Document")->GetBool("DisablePBuffers",!pbuffer)) {
         this->createThumbnailFromFramebuffer(img);
     }
     else {

src/Gui/View3DInventor.cpp

@@ -35,6 +35,7 @@
 # include <QFileDialog>
 # include <QGLFormat>
 # include <QGLWidget>
+# include <QGLPixelBuffer>
 # include <QPainter>
 # include <QPrinter>
 # include <QPrintDialog>
@@ -532,8 +533,9 @@ void View3DInventor::print(QPrinter* printer)
     QPainter p(printer);
     QRect rect = printer->pageRect();
 
+    bool pbuffer = QGLPixelBuffer::hasOpenGLPbuffers();
     if (App::GetApplication().GetParameterGroupByPath
-        ("User parameter:BaseApp/Preferences/Document")->GetBool("DisablePBuffers",false)) {
+        ("User parameter:BaseApp/Preferences/Document")->GetBool("DisablePBuffers",!pbuffer)) {
         previewFromFramebuffer(rect, img);
     }
     else {

src/Gui/View3DPy.cpp

@@ -29,6 +29,7 @@
 # include <QColor>
 # include <QImage>
 # include <QGLFramebufferObject>
+# include <QGLPixelBuffer>
 # include <Inventor/SbViewVolume.h>
 # include <Inventor/nodes/SoCamera.h>
 #endif
@@ -696,8 +697,9 @@ Py::Object View3DInventorPy::saveImage(const Py::Tuple& args)
         bg.setNamedColor(colname);
 
     QImage img;
+    bool pbuffer = QGLPixelBuffer::hasOpenGLPbuffers();
     if (App::GetApplication().GetParameterGroupByPath
-        ("User parameter:BaseApp/Preferences/Document")->GetBool("DisablePBuffers",false)) {
+        ("User parameter:BaseApp/Preferences/Document")->GetBool("DisablePBuffers",!pbuffer)) {
         createImageFromFramebuffer(w, h, bg, img);
     }
     else {